Obviously, we can get more complex than that but that’s the basic couple of questions at the root of it all.

The answers to 2) that we have all been working to came from the SRES, the Special Report on Emissions Scenarios. A report I’ve had great fun with as it shows that globalisation reduces emissions for any given level of population or wealth. Entirely contrary to the bleatings of every damn greenie on the planet.

The SRES families and scenarios were based on a pretty obvious methodology. Work out how many people there are going to be, how rich they’re going to be and which technologies they’re going to use and this will tell you what emissions are going to be. You can then plug those numbers into your climate models and Bob’s your parental sibling of choice.

The SRES was getting a bit old, probably is/was right to update it.But do note one thing about the method used to prepare the SRES. It started with the economics. As it has to. Wealth to a large extent determines population, technology to some/a large extent determines wealth and so on. So to decide upon emissions levels you’ve got to start with the economics of how many people will there be doing what which which machines?

The next IPCC report will be based upon the updates to the SRES. Great, that’s fine. But note how they’re updating the SRES. They’re not starting with the economics. Ooooooh no, that would be far too sensible. What they’ve actually done is made up some emissions levels.

No, really, they have. They’ve simply plucked numbers from nowhere to give emissions levels. It’s in the future that they’re going to go back and work out the economics of how those emissions are produced.

Which is, of course, entirely insane.

Now, of course, it’s possible that I’ve got this completely wrong. If so please do tell me. But if I haven’t, if I’m actually correct, then the entire IPCC process becomes an entire heap of steaming donkey’s bollocks.

They have, quite literally, just made up the numbers that the whole thing’s based upon.

No, seriously, this is insane:

The socioeconomic scenarios underlying the RCPs cannot be treated as a set with an overarching internal logic. While each individual RCP was developed from its own internally consistent socioeconomic foundation, the four RCPs as a group were selected on the basis of their concentration and forcing outcomes to be ompatible with the full range of emissions scenarios available in the literature. Therefore, there is no overarching logic or consistency to the set of socioeconomic assumptions or storylines associated with the set of RCPs. In particular, the socioeconomic scenario underlying one RCP should not be used in conjunction with that of another RCP, and cannot be freely used interchangeably with the assumptions underlying other RCPs. Furthermore, the set of underlying socioeconomic scenarios is not intended to span the range of plausible assumptions for any particular socioeconomic element (population, gross domestic product growth, rates of technological change, land use, etc.).

The only thing we’re bloody interested in is the socioeconomic policies that we can use to avoid boiling Flipper. And they’re going to base the entire edifice on socioeconomic scenarios that aren’t even logically consistent with each other?

What crazed lunacy is this?

And worse. I think this is the paper that is used to underpin the high estimate. And they deliberately, explicitly, ignore the A1 scenarios from the SRES. They offer adaptations only of A2, B1 and B2.

That is, they entirely ignore the best explored of the earlier families. The one where we all get rich through globalised capitalism and either don’t stop using fossils (A1F1) or do (A1T).

Err, A1T being the one where we all get rich, we abolish poverty globally, we don’t boil the planet because renewables get cheap enough to use and we do this all through globalised capitalism.

It’s an interesting model to leave out really, isn’t it?

Somebody, please, tell me they’re not trying to base the future of the world on this analysis?